External VNR speed improvement and more.

webrtc/modules/video_processing/util/noise_estimation.h

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
 #ifndef WEBRTC_MODULES_VIDEO_PROCESSING_UTIL_NOISE_ESTIMATION_H_
 #define WEBRTC_MODULES_VIDEO_PROCESSING_UTIL_NOISE_ESTIMATION_H_
 
 #include "webrtc/base/scoped_ptr.h"
 #include "webrtc/modules/include/module_common_types.h"
 #include "webrtc/modules/video_processing/include/video_processing_defines.h"
 #include "webrtc/modules/video_processing/util/denoiser_filter.h"
 
 namespace webrtc {
 
-#define EXPERIMENTAL 0
 #define DISPLAY 0
 
 const int kNoiseThreshold = 200;
 const int kNoiseThresholdNeon = 70;
 const int kConsecLowVarFrame = 6;
 const int kAverageLumaMin = 20;
 const int kAverageLumaMax = 220;
 const int kBlockSelectionVarMax = kNoiseThreshold << 1;
 
+// TODO(jackychen): To test different sampling strategy.
+// Collect noise data every NOISE_SUBSAMPLE_INTERVAL blocks.
+#define NOISE_SUBSAMPLE_INTERVAL 41
+
 class NoiseEstimation {
  public:
   void Init(int width, int height, CpuType cpu_type);
+  // Collect noise data from one qualified block.
   void GetNoise(int mb_index, uint32_t var, uint32_t luma);
+  // Reset the counter for consecutive low-var blocks.
   void ResetConsecLowVar(int mb_index);
+  // Update noise level for current frame.
   void UpdateNoiseLevel();
   // 0: low noise, 1: high noise
   uint8_t GetNoiseLevel();
 
  private:
   int width_;
   int height_;
   int mb_rows_;
   int mb_cols_;
+  int num_noisy_block_;
+  int num_static_block_;
   CpuType cpu_type_;
   uint32_t noise_var_;
   double noise_var_accum_;
-  int num_noisy_block_;
-  int num_static_block_;
   double percent_static_block_;
-  rtc::scoped_ptr<uint32_t[]> consec_low_var_;
+  std::unique_ptr<uint32_t[]> consec_low_var_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_VIDEO_PROCESSING_UTIL_NOISE_ESTIMATION_H_